title: Outbreak of Klebsiella pneumoniae carbapenemase 2-producing K. pneumoniae with high qnr prevalence in a Chinese hospital.
abstract: Forty carbapenem-resistant Klebsiella pneumoniae isolates were recovered from 28 patients from various sites in an intensive care unit in Zhejiang Provincial People's Hospital, China, over a 6 month period. PFGE analysis indicated that the 40 strains were all closely related. The MICs of carbapenems varied from 16 to >256 µg ml⁻¹. Conjugation studies with Escherichia coli resulted in the transfer of reduced carbapenem susceptibility from the original isolates. All K. pneumoniae and E. coli transconjugants produced K. pneumoniae carbapenemase 2 (KPC-2), and most of them produced TEM, SHV and CTX-M. Additionally, 27 isolates and 27 E. coli transconjugants carried the qnr gene (25 were qnrB2 and 2 were qnrS1). K. pneumoniae harboured several plasmids, and bla(KPC-2) was located on a 55 kb plasmid. SDS-PAGE and ompK35/36 gene sequence analysis of OMPs suggested that porins in K. pneumoniae are expressed normally. The MICs of the carbapenems did not change in the presence of CCCP. Thus, production of KPC-2 appears to play an important role in resistance to carbapenems, although other mechanisms may be involved. The bla(KPC-2) gene is associated with several antibiotic-resistance genes, such as bla(TEM), bla(SHV), bla(CTX-M) and qnr.
authors.affiliation: 2nd Affiliated Hospital of Zhejiang University, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, PR China.
authors.forename: Rong
authors.initials: R
authors.lastname: Zhang
authors.affiliation: 2nd Affiliated Hospital of Zhejiang University, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, PR China.
authors.forename: Xuan Ding
authors.initials: XD
authors.lastname: Wang
authors.affiliation: 2nd Affiliated Hospital of Zhejiang University, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, PR China.
authors.forename: Jia Chang
authors.initials: JC
authors.lastname: Cai
authors.affiliation: 2nd Affiliated Hospital of Zhejiang University, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, PR China.
authors.forename: Hong Wei
authors.initials: HW
authors.lastname: Zhou
authors.affiliation: Zhejiang Provincial People's Hospital, 158 Shangtang Road, Hangzhou 310009, PR China.
authors.forename: Huo Xiang
authors.initials: HX
authors.lastname: Lv
authors.affiliation: Zhejiang Provincial People's Hospital, 158 Shangtang Road, Hangzhou 310009, PR China.
authors.forename: Qing Feng
authors.initials: QF
authors.lastname: Hu
authors.affiliation: 2nd Affiliated Hospital of Zhejiang University, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, PR China.
authors.forename: Gong-Xiang
authors.initials: GX
authors.lastname: Chen
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D015780:Carbapenems / Q000494:pharmacology*; D002681:China / Q000453:epidemiology; D024881:Drug Resistance, Bacterial; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D006801:Humans; D007710:Klebsiella Infections / Q000453:epidemiology / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D015780:Carbapenems; C485385:Qnr protein, Klebsiella pneumoniae; D001618:beta-Lactamases; C531581:carbapenemase-2, Klebsiella pneumoniae